Child Support Calculator
Australia 2026, Step by Step

With the 8-step basic formula: each parent's adjusted taxable income minus the $31,046 self-support amount; their combined income; each one's income percentage; each one's percentage of care and the cost percentage it gives; the child support percentage (income percentage minus cost percentage); the costs of the children from the 2026 table; and finally child support percentage × costs.

$31,046, one-third of the $93,137 annualised male total average weekly earnings figure. It is taken off each parent's income before anything is shared, and it is updated every 1 January.

Care is counted in nights a year. Under 14% (about 1 night a fortnight) counts for nothing; 14% to under 35% gives a 24% cost percentage; from 35% it rises 2 points per percentage point, reaching 50% at 48-52% care.

The parent with more care has the higher cost percentage, so the more nights you have, the less you pay or the more you receive.

$551 a year for 2026, the minimum annual rate. It applies when a parent has less than 14% care and the formula would otherwise give less, for example because their income is below the self-support amount.

A parent with very low income can apply to have it reduced to nil.

Adjusted taxable income: taxable income plus certain amounts such as reportable fringe benefits, reportable super contributions, net investment losses, tax-free pensions and target foreign income. Enter that figure for each parent; if you only know taxable income, the estimate will be lower than the assessment for anyone with those extra items.

No. Services Australia makes the assessment. This calculator covers the basic formula for one family with two parents and the same care for every child.

It does not handle children from other relationships, a grandparent or other non-parent carer, multiple cases, the fixed annual rate or a change of assessment.